Biomedical subjects
Publications and source records attributed to Jingbo Zhang.
This article describes the principles, attributes, and pitfalls of the many MR imaging approaches available for assessment of renal-related disorders. Tables 1 and 2 summarize the specific approach and rationale.
RATIONALE AND OBJECTIVES: Investigators in this study compared standard-dose and low-dose inspiratory and expiratory computed tomographic (CT) images with regard to their usefulness for measuring the tracheal lumen in patients with or without tracheobronchomalacia (TBM). MATERIALS AND METHODS; Hospital records were reviewed to identify 10 consecutive patients with bronchoscopically proved TBM and 10 control subjects without TBM who underwent paired volumetric inspiratory and dynamic expiratory examinations with multisection CT. A low-dose (40-80 mA) technique was used for dynamic expiratory CT in 14 (70%) of the 20 subjects, and a standard dose (240-280 mA) was used in the remaining six (30%). All images were reviewed in a randomized, blinded fashion by two observers, who measured the tracheal lumen to determine the presence of TBM by consensus. The degree of confidence in measuring the tracheal lumen was graded on a four-point scale from 0(no confidence) to 3 (highest level of confidence), also by consensus of the two observers. Statistical analysis for differences in confidence level was performed with the Mann-Whitney U test. The image noise level was assessed by measuring the standard deviation of the presternal soft tissue, and statistical analysis for differences in noise level was performed with the t test. RESULTS: The level of confidence in tracheal lumen measurement was high, regardless of respiratory phase and dose (inspiratory mean, 2.9; median, 3; range, 2-3; expiratory low-dose mean, 2.6; median, 3; range, 2-3; expiratory standard-dose mean, 2.8; median, 3; range, 2-3). There was no significant difference in confidence level between standard- and low-dose techniques (P = .53). Excessive central airway collapse (expiratory reduction in cross-sectional diameter, > 50%) was seen in all 10 patients with TBM and in none of the control subjects. CONCLUSION: The acquisition of paired inspiratory and dynamic expiratory images with multisection helical CT is a promising method for diagnosing TBM. The low-dose technique performs as well as the standard-dose technique for the dynamic expiratory phase, with a similar degree of confidence for measuring the tracheal lumen.
OBJECTIVE: Searching for more potent and less toxic HMBA-related agents. METHODS: Human erythroleukemia cell K562, murine erythroleukemia cell (MEL) and its sub-line MEL DS19 were used as target cells to select a cell line which is the most sensitive to HMBA, then analyzed the activity of inducing differentiation of two new designed HMBA derivatives: HMBPA [hexamethylenebi (3-pyridin) amide] and Co-HDTA (ethylenediaminetetra acetic acid cobalt) using cell biology, cytochemical and molecular biology techniques. RESULTS: We found that the MEL DS19 cells were most sensitive to HMBA (benzidine positive, B+ approximately 76%). Co-HDTA can inhibit the growth of MEL DS19, but induces differentiation just in a small population (B+ 2% approximately 4.5%). Between 0.02 approximately 5 micromol/L, HMBPA induces 3% approximately 8% cells committed to differentiation with little inhibition of cell proliferation. 1 micromol/L HMBPA and 2 mmol/L HMBA together, can obviously increase the percentage of differentiated cell (B+ approximately 72%), inhibit DNA synthesis and accelerate beta-globin transcription. CONCLUSION: The new HMBA derivatives may provide potential cancer differentiation inducers.
MR imaging is useful in differentiating and characterizing renal masses. A careful evaluation of the signal characteristics and morphology of a renal mass combined with the ancillary imaging findings and patient history should assist the radiologist in making the proper diagnosis or recommending the appropriate treatment in most cases. This pictorial essay demonstrates the typical MR imaging features of common renal masses including renal cell carcinoma (RCC), oncocytoma, angiomyolipoma, metastases, transitional cell carcinoma (TCC), lymphoma, and arteriovenous malformation (AVM), and highlights several potential diagnostic pitfalls in making the proper diagnosis.
BACKGROUND: Renal tubular epithelial cells (TECs) function as antigen-presenting cells because they constitutively express MHC class II molecules and have the ability to present peptide antigen to CD4+T cells. However, the costimulatory signals provided by TECs for optimal T-cell activation have not been fully characterized. Increasing recognition of the importance of B7 dendritic cells (B7-DC) in immunoregulation raises the question of whether B7-DC is expressed on TECs and is involved in regulating TEC function. METHODS: B7-DC on cultured human and murine TECs was detected by flow cytometry in vitro. Immunohistochemistry was performed on human kidney biopsies. Coculture experiments were performed to confirm the role of TEC-related B7-DC in regulating CD4+T-cell activation. RESULTS: Data revealed that B7-DC is specifically expressed on TECs with inflammatory factor induced and diseased human kidney samples, including chronic glomerulonephritis, lupus nephritis, tubulointerstitial nephritis and renal cell carcinoma. B7-DC was a strong inhibitor of CD4+T-cell activation, as assessed by increased cytokine (interferon-gamma and interleukin-2) production and enhanced levels of T-cell activation marker CD69 in the presence of its blocking antibody. Blocking B7-DC/PD-1 enhanced antigen presentation. B7-DC is especially well expressed on TECs of diseased kidney samples and significantly down-regulates T-cell activation. CONCLUSIONS: We speculate that B7-DC might play an important role in maintaining peripheral tolerance, and in protecting the epithelium from immune-mediated tubulointerstitial injury.